Rails scaffold with Bootstrap 4

_form.html.erb

<%%= form_with(model: <%= model_resource_name %>, local: true) do |form| %>
  <div class="card mb-4">
    <div class="card-body">
      <%% if <%= singular_table_name %>.errors.any? %>
        <div id="error_explanation" class="alert alert-danger">
          <h2 class="h4"><%%= pluralize(<%= singular_table_name %>.errors.count, "error") %> prohibited this <%= singular_table_name %> from being saved:</h2>

          <ul>
          <%% <%= singular_table_name %>.errors.full_messages.each do |message| %>
            <li><%%= message %></li>
          <%% end %>
          </ul>
        </div>
      <%% end %>

    <% attributes.each do |attribute| -%>
      <div class="form-group">
    <% if attribute.password_digest? -%>
        <%%= form.label :password %>
        <%%= form.password_field :password, class: 'form-control' %>
      </div>

      <div class="form-group">
        <%%= form.label :password_confirmation %>
        <%%= form.password_field :password_confirmation, class: 'form-control' %>
    <% else -%>
        <%%= form.label :<%= attribute.column_name %> %>
        <%%= form.<%= attribute.field_type %> :<%= attribute.column_name %>, class: 'form-control' %>
    <% end -%>
      </div>

    <% end -%>
      <div class="form-group mb-0">
        <%% if <%= model_resource_name %>.persisted? %>
          <div class="float-right">
            <%%= link_to 'Destroy', <%= model_resource_name %>, method: :delete, class: "text-danger", data: { confirm: 'Are you sure?' } %>
          </div>
        <%% end %>

        <%%= form.submit class: 'btn btn-primary' %>

        <%% if <%= model_resource_name %>.persisted? %>
          <%%= link_to "Cancel", <%= model_resource_name %>, class: "btn btn-link" %>
        <%% else %>
          <%%= link_to "Cancel", <%= index_helper %>_path, class: "btn btn-link" %>
        <%% end %>
      </div>
    </div>
  </div>
<%% end %>

edit.html.erb

<h1>Edit <%= singular_table_name.capitalize %></h1>

<%%= render 'form', <%= singular_table_name %>: @<%= singular_table_name %> %>

index.html.erb

<div class="row">
  <div class="col-sm-6">
    <h1><%= plural_table_name.capitalize %></h1>
  </div>

  <div class="col-sm-6 text-right">
    <%%= link_to "Add New <%= human_name %>", new_<%= singular_table_name %>_path, class: 'btn btn-primary' %>
  </div>
</div>

<div class="table-responsive">
  <table class="table table-hover">
    <thead>
      <tr>
        <%- attributes.each do |attribute| -%>
        <th><%= attribute.human_name %></th>
        <%- end -%>
        <th></th>
      </tr>
    </thead>

    <tbody>
      <%% @<%= plural_table_name%>.each do |<%= singular_table_name %>| %>
        <%%= content_tag :tr, id: dom_id(<%= singular_table_name %>), class: dom_class(<%= singular_table_name %>) do %>
          <%- attributes.each do |attribute| -%>
          <td><%%= <%= singular_table_name %>.<%= attribute.name %> %></td>
          <%- end -%>
          <td><%%= link_to 'Show', <%= singular_table_name %> %></td>
        <%% end %>
      <%% end %>
    </tbody>
  </table>
</div>

new.html.erb

<h1>New <%= singular_table_name %></h1>

<%%= render 'form', <%= singular_table_name %>: @<%= singular_table_name %> %>

show.html.erb

<div class="page-header">
  <div class="row">
    <div class="col">
      <%%= link_to "All <%= plural_table_name.capitalize %>", <%= index_helper %>_path, class: 'btn btn-default' %>
    </div>
    <div class="col text-right">
      <%%= link_to "Edit", edit_<%= singular_table_name %>_path(@<%= singular_table_name %>), class: 'btn btn-primary' %>
    </div>
  </div>
  <h1>Show <%= singular_table_name %></h1>
</div>

<dl class="dl-horizontal">
  <%- attributes.each do |attribute| -%>
  <dt><%= attribute.human_name %>:</dt>
  <dd><%%= @<%= singular_table_name %>.<%= attribute.name %> %></dd>
  <%- end -%>
</dl>

@tomash Ops. I think this should work , I pulled it from old project, I don't use bootstrap anymore

<%%= form_with(model: <%= model_resource_name %>, local: true) do |form| %>
  <div class="card mb-4">
    <div class="card-body">
      <%% if <%= singular_table_name %>.errors.any? %>
        <div id="error_explanation" class="alert alert-danger">
          <h2 class="h4"><%%= pluralize(<%= singular_table_name %>.errors.count, "error") %> prohibited this <%= singular_table_name %> from being saved:</h2>

          <ul>
          <%% <%= singular_table_name %>.errors.full_messages.each do |message| %>
            <li><%%= message %></li>
          <%% end %>
          </ul>
        </div>
      <%% end %>

    <% attributes.each do |attribute| -%>
      <div class="form-group">
    <% if attribute.password_digest? -%>
        <%%= form.label :password %>
        <%%= form.password_field :password, class: 'form-control' %>
      </div>

      <div class="form-group">
        <%%= form.label :password_confirmation %>
        <%%= form.password_field :password_confirmation, class: 'form-control' %>
    <% else -%>
        <%%= form.label :<%= attribute.column_name %> %>
        <%%= form.<%= attribute.field_type %> :<%= attribute.column_name %>, class: 'form-control' %>
    <% end -%>
      </div>

    <% end -%>
      <div class="form-group mb-0">
        <%% if <%= model_resource_name %>.persisted? %>
          <div class="float-right">
            <%%= link_to 'Destroy', <%= model_resource_name %>, method: :delete, class: "text-danger", data: { confirm: 'Are you sure?' } %>
          </div>
        <%% end %>

        <%%= form.submit class: 'btn btn-primary' %>

        <%% if <%= model_resource_name %>.persisted? %>
          <%%= link_to "Cancel", <%= model_resource_name %>, class: "btn btn-link" %>
        <%% else %>
          <%%= link_to "Cancel", <%= index_helper %>_path, class: "btn btn-link" %>
        <%% end %>
      </div>
    </div>
  </div>
<%% end %>